Process of making structural material by heat bonding wire filaments



y 1958 J. s. NACHTMAN ETAL 2,842,440 PROCESS OF MAKING STRUCTURAL MATERIAL BY HEAT BONDING WIRE FILAMENTS Filed Dec. 18, 1953 Hear mum:

' INVENTORS JOHN 5. NA CH TMA/V BY JOHAN BQR/(Sfi I /L M20 Attorney PROCESS OF .Qther ,metals, .melting MAKING STRUCTURAL MATERIAL BY HEAT BONDING WIRE FILAMENTS John Simon Nachtman, Washington, D. C., and

' Johan Bjorksten, Madison, Wis.

Application December 18, 1953, Serial No. 399,085

7 Claims. (Cl. 75-208) United States Patent This invention relates to making a structural material 'by laminating metallic filaments provided with essentially metallic coatings and to shaped bodies made in this way.

it is well known that molecular orientation of a material such as a metal is often produced by drawing such material into the form of fine filaments. Fine filaments of such a material exhibit remarkably vhigh tensile strength. The possibilities of providing a structural ma terial ofv extremely high tensile strength by utilizing filaments of-this type provided with metallic coatings have 0 not heretofore been fully realized.

,;It is there-forean object of this invention to provide a method for making structural material of extremely high rtensile strength by utilizing metallically coated metallic.

filaments. 7

Another object is a method formaking a shaped me- :tallic body by laminating together fine metallic filaments provided with coatings of metal or metaloxide.v I

formed in this manner. ,1

.fliFtli'tllel; objects will become apparent from the drawing and the following detailed description in which it is our intention to illustrate the applicability of the invention without thereby limiting its scope to 1 less than that of all' those equivalents skilled in the'art. I p

The drawing is a cross-sectional schematic view; showing the preparation of coated metallic filaments suitable:

which be apparent to those for the invention.

' In accordance *with a preferred embodiment of our invention we coat a steel rod 1 with copper coating 2 by electroplating and draw the resultant coated rod through aidi'e 4 to reduce its diameter to from/.020toz0005 inch; I A' layer'of, generally parallel coated filaments prepared inithis manner or prepared by coating previously. drawn filaments'is placed, between suitably 'shaped' -p1-atens or dies; and the copper coatings arecombined into a; continuous; media of copper surrounding the steel filaments "bytheating the structure or..'by heating the structure. and at the same time. exerting pressure thereon or byexertz ',30 fAnother object is a shaped body of structural material The coating 2 which may be placed on the rod prior to drawing or placed on the filamentafter drawing may suitably comprise one ,or more of the abovemetals or alloy thereof or one or more of the following'metals or alloy thereof: 7 Y

Antimony Indium Bismuth Zincv Cadmium Lead The metals herewith stated as being suitable for'coat ing metals may also be utilized in alloys'suitable for pro- Viding'filaments. Similarly metals listed above as particularly suitable for providing filaments may be utilizedin alloys suitable for coatings. The coating may also comprise an oxide of a metal or anoxidation product of. a metal alloy. 7

The coating need not consist of only onemetal, metal alloy thereof, or oxide; the rod or filament may be coated first with one metal or alloy thereof, then may be addi tionally coated with another metal oralloy thereof, then maybe coated additionally with another metal or alloy thereof. The rod (prior'to drawing) or filament (after drawing) vthus coated maybe heated to cause diffusion of A the metals of the several coatings into one another or to cause diffusion of the icoating next to the rod or filament 4 into the rod or filament itself, or both. 4

The coating may be applied by any one of the meth-;

ods known to the art. The metal coating maybe applied by gas-plating, 'e; g. by passinga hot metal rod or filament through a gaseous metallic compound such as a i metallic carbonyl, formate, hydride, or the like, adapted to decompose upon contact with the hot rod or filament and to deposit thereon the metal of the aforesaid metal compound as a decomposition product, A metal coating may be deposited by electroplating. A coating may 7 be deposited by'evaporation of the coating material in a vacuum, also referred to as vacuum-sputtering or vacuum spattering. The rod or filament to be coated may 'be passed through a molten bath of the coating metal. A metal may also be coated onto the rod or filament by passing through a bath of a light hydrocarbon vehicle having suspended therein particles of the coating metal and then passing the rod or filament througha furnace to 1 cause the hydrocarbon vehicle to evaporate and to cause ing pressure thereon without substantial heating. The Y optimum temperature is'in any event below the melting point of the coating metal forheavy coatings, but at any temperature,jeven above the melting point, for thin coatings, 4

Instead of providing the metallicallycoated metal fila-' ment by drawing a coated rod through a die we may also suitably coat afine metal filament after. it is drawn. Y

1111 accordance .with our invention we mayuseanyon'e or.frnore of thevfollowing metals or alloys thereof as i'na i' terialsfrom which to make the filamentst,

-Bronze.

Steel Stainless steel .v I Tin.

Chrome steel Cobalt 1 -Monel ,7 Zirconium N el-.- 4 1 m m;. Copper L Molybdenum adaptedto provide strong filaments? preferably Iab o'v e 900 and 1 You the particles of coating metal deposited thereon to coalesce into a continuous coating. The metal, or alloy thereof, or oxide thereof, may be coated by dipping a rod or filament in a solution or suspension of a compound of the material to be deposited thereon. The article thus coated with solution may be removed from thebath and heated to cause decomposition of the compound and dep-- 4 osition ofthe material to be coated. Asshown in the figure, heat 3 is applied to rod 1 pro vlded with coating 2 which is continuously drawn through a die .4 to .provide coated filaments.

for example, a bronze coating by causing a tincoating Y and a copper coating to diifuse into one another; inorder to provide astainless steel coating by causing layers of; 7

copper, nickel and steel to diffuse into one another; for

filament resulting from its.

to provide a Monel coating by causing layers of nickel and copper to diffuse into one another.

In accordance with the invention, laminates are made from the coated filaments prepared as described above. Such laminates consist of thefilaments bonded together with the material of'the coating thereonby difiusion of the coating material on each filament into the coating material on adjacent filaments. Laminates are formed by placing a suitably large bundle of coated fibers between platens o-r shaped dies of a press or rolls of a rolling mill Without the addition of a metal or metallic compound or any other compound as abinder material. Sufiicient pressure is exerted by the platens or dies or rolls to force the bundle into a compact mass. Bonding may then be. caused to occur by applying heat or pressure (as in cold rolling) or both heat and pressure. Generally the application of both heat and pressure is preferred, the heat being sufficient to cause bonding by diffusion without heating the filament material to a temperature which would be deleterious to the physical properties of the filaments.

The terms continuous medium, continuous media, continuous bonding medium and continuous bonding agent are used throughout to refer to material which extends throughout an article or shaped body-in such a manner that a theoretical point contained within the interior of the bonding material may travel from any point on any surface of the article to any other point on any other surface without passing outside of said housing material or passing through any interface between said bonding material and any other material.

The invention is further illustrated by the following examples:

Example 1 A rod A inch in diameter and 6 feet long of SAE 1066 steel is placed in a copper electroplating bath and copper is electroplated thereon until the plating has reached a thickness of approximately .020 inch. The coated rod is then heated, one end is swaged and passed into a die as shown in the illustration and the coated rod is drawn down to a coated filament having an approximate outside diameter of .002 inch, the filament having a very thin coating of copper.

Such filaments are placed between platens of a press; heat and pressure are exerted thereon to provide a flat structural article of a high tensile strength, comprising a continuous medium of copper having steel filaments disposed therethrough.

Example 2 Filaments prepared in accordance ith Example 1 are immersed in an electroplating bath; nickel is plated thereon. The resultant copper coated filaments having a nickel outer coating are heated to cause slight difiusion of the nickel coating into the copper coating; layers of such filaments in somewhat parallel relationship are placed between matched metal dies in a press so that each filament extends at least from one side of the mold cavity to the other side and heated while being maintained under pressure to provide a shaped article of great strength, with a continuous media of nickel as bonding agent.

Example 3 A bundle of filaments prepared as in Example 1 are placed between shaped ceramic dies so that all filaments extend beyond the die cavity at each end and heated at below the melting point of the copper coating while being maintained under contact pressure to provide a structural article comprising steel filaments bonded together with a substantially continuous medium of copper, having great strength.

Laminates prepared in accordance with the invention may be heat-treated to improve their properties but care 4 must be exercised to avoid undesired loss of properties in the fine filaments.

Example 4 A rod inch in diameter of A181 C1141 steel is coated with a .026 inch coating of nickel by electroplating. The rod thus nickel coated is drawn down to a diameter of .125 inches and then swaged and then passed through progressive dies while still above the softening temperature until .020 inch in diameter. At the output end of the .020" diameter die it is heated and then by drawing at high speed drawn down to .005 to .010" diameter.

The extremely fine filaments prepared in this manner are provided with an additional coating of nickel by gasplating from nickel carbonyl and are then placed between shaped polished matched steel dies in a press and subjected to a pressure of approximately 90,000 pounds per square inch, which is maintained for approximately one hour while the dies are maintained at a temperature below the meltingpoint of the nickel and the steel, sufiiciently low to avoid deleterious effect on the tensile strength of the steel filaments resulting from their orientation during drawing. The steel filaments are thus bonded with a continuous meduim of nickel.

Example 5 Copper wire .0035 inch in diameter is passed through a bath of molten lead. A thick plate is formed by pressing a bundle of such coated wires between matched metal dies at approximately 50,000 pounds per square inch.

Example 6 Steel music wire (SAE 1085 steel) .007 inch in diameter is coated by passing it through a molten bath of zincaluminum alloy sold commercially as Zamac 3. A bundle of wire thus coated is placed between dies in a press so that each filament extends beyond the die cavity and a valve housingis made by pressing at 900 pounds per square inch and heating to the melting point of said alloy to cause the coatings'to diffuse into one another.

Example 7 A nickel rod (melting at approximately 2646 F.) having a diameter of approximately .005 inch is provided with a coating of silicon bronze by casting'around the rod a molten alloy having the composition:

Percent Copper 95.8 Manganese 1.1 Silicon 3.1

The coated rod is drawn through a series of dies to reduce its diameter to .002 inch. Layers of the resulting coated filaments are placed between the platens of a press and subjected to heat and pressure to form a reinforced structural plate of-high tensile strength.

Example 8 A tungsten wire .005 inch in diameter is coated with an aluminum bronze by drawing it. at a sharp angle over a series of ten blocks of an alloy having the composition:

Percent Copper 91.10 Aluminum '7 .0 Silicon 2.0

ing metal.

coating to partially diffuse into one another.

matched metal dies'in a press and an aircraft-component is made by applying heat and pressure. 1 a

Exampl of a press in such manner that the filaments in each layer are parallel to .one another and filaments in one layer are at' an angle'to the filaments in the next adjacent layer.

The filaments are subjected to heat and pressure and the tinis thus caused'bydiffusion to provide a continuous bondingmedia, In this manner is formed a plate cntaining steel. filaments: extending from one part of the plate to the other in laye1's, the filaments in each layer being parallel and the layers being parallel 'to one an other, bonded together, with'a continuous bonding media of'tin.

."It may be-"seen that in each of the examples, the article made according to the invention is porous if thin coatings are provided on the filaments and'is non-porous it relatively thick coatings are provided on the filaments. Only, the coating material is provided as material adapted to'fill the interstices between the filaments of higher melt- No additional bonding agent is provided as would be the case if molten metal were cast on the filaments. Thus by controlling the thickness of coating we may control the size of the interstices and thus adjust the properties which we wish to obtain. By providing relatively large interstices we may provide a material which has great strength while being relatively light. On the I other hand for some applications we may wish to provide a material which is particularly resistant to passage of liquids or gases therethrough and in this event we would j generally provide filaments with relatively thick coatings so that upon being subjected to high pressure and to a temperature adapted to cause difiusion of the coating material, the material of the coatings will flow together and fill the interstices.

Example V A single layer of parallel strands of tin-coatedicopper wire is cold-rolled to provide a flatsheet and immediately heat-treated to provide a bonded flat sheet by diffusion of the tin at the adjacent surfaces.

Example 11 Two layers of bronze-coated nickel wire are heated and passed between a pair of hot rolls while being maintained in the form of two layers of parallel wires, the

wires in one of the two layers being at an angle to those in the other layer. wires bonded together by partial diffusion of the coating on each wire intothe coating of the adjacent wires, is thus formed. The article thus comprises filaments of nickel extending from one side of the article to the other bonded with a continuous media of copper.,

Example 12 I of a press adapted to provide an article such as. a gear housing. The press is then closed. and the structure is ment into the coating of each adjacent filament, to thereby bond the filaments together. I

' The article is then removed and as thus prepared com' I It may thus be seen that our invention relates toshaped.

bodies, structural shapes or the like comprising filaments whichextend from one side ofthe body to the other side ofthebody.-,

Our invention further relates tosuch articles, in: which bonding between the filaments. is provided :by a continue wherein bonding is accomplished by difiusion of the coat. ing material of each filament into coating: material of, adjacent filaments. J

Our invention further relates to such articles or bodies wherein bonding is provided entirely bycoating'provided' on the filaments, without the addition of any additional 7 material such as might be provided by casting molten welding alloy or the metalaroundthe filaments or adding solder oreutectic like in the form of wire or rods or the like. i Metal oxides may be properties. 7 v

It may thus be seen'that the invention is broad inscope and is not to be limited excepting by the claims.

A flat article comprising flattened maintained at a temperature adapted to provide for substantially complete diffusion of the materials of the two coatings into one another and for a time sufiicient to provide for. partial difiusion of the coating of each fila- Having thus disclosed our invention, We claim: 1. The process of providing a shaped'body comprising metal wire filaments extending therethrough which comprises the steps of providing a plurality of metal wire filaments .001 to .010" in diameter coated with at least two layers .00001 to .001" thick each of said layers being a non-powdered continuous substantially homogeneous substance selected from the group consisting of metals and oxides thereof of different composition than said filament, compacting a group of said filaments under pressure sufficiently low to prevent elongation and crosssectional deformation of said filaments and while maintaining such pressure thereon, applying heat to said compacted mass at a gradually increasing rate to alloy said layers with each other to thereby join said .filamentstogether, said heat being applied at a rate which prevents the temperature of said compacted mass from exceeding the melting point of any componentthereof.

2. The process of claim 1 characterized by causing said filaments to be oriented parallel to one another prior to being compacted.

3. The process of claim 1 characterized by causing a portion of said filaments in said group to be parallel to one another and another portion of said group of fila ments to be parallel to one another but to be at an angle to the filaments in said-first portion.

4, The process of claim 1 further characterized by providing said group of filaments by first laying a group of coated filaments parallel to one another in a bottom mold half .and then laying a second group of filaments parallel to one another but at an angle to said first group of filaments on top of said first group, and by then compacting the resultant assembly of such coated filaments by forcing a top mold halfagainst said bottom mold half.

5. The process of claim 1 further characterized by commencing said heating with said compacted filaments at a temperature below 200 F. and then heating said filaments over a period of at least one half hour to a temperature above ,800" F. and below the transition temperature of the metal of the filaments. p

' 6. The process of providing a shaped body comprising metal wire filaments extending therethrough which comprises the steps of providing a plurality of ferrous alloy wire filaments .001" to .010" in diameter coated with at least two layers .0000'1 to .001" thick, each of said layers being a non-powdered continuous substantially homounder pressure sufliciently low to prevent elongation and cross-sectional deformation of said filaments and while utilized to provi de insulating maintaining such pressure thereon, applying heat to said compacted mass at a gradually increasing rate to alloy said layers with each other to thereby join said filaments together, said'heat being applied which prevents the temperature of said compacted mass from exceeding the melting point of any component thereof, further characterized by commencing said heating with said compacted filaments at a temperature below 200 F and then heating said filaments over a period of at least one half hour to a temperature above 800' F. and below the transition temperature of the metal of said filaments.

7. The process of providing a shaped body comprising metal wire filaments extending therethrough which comprises the steps of providing a plurality of metal wire filaments .001" to .010 in diameter coated with at least one layer .00001 to 001" thick, said layer being a nonpowdered continuous substantially homogeneous substance selected from the group consisting of metals and oxides thereof of diiferent composition than said filament, compacting a group of said filaments under pressure sufliciently low to prevent elongation and crosssectional deformation of said filaments and while maintaining such pressure thereon, applying heat to said coinpactedmass at a gradually increasing rate to alloy said layers in adjacent-filaments with each other to thereby join said filaments together, said heat being applied at a rate which prevents the temperature of said compacted mass from exceeding the melting point of any component thereof.

References Cited in the file of this patent UNITED STATES PATENTS 867,659 Hoopes Oct. 8, 1907 1,292,659 Speed Jan. 28, 1919 1,336,449 Trunk Apr. 13, 1920 1,704,256 Lorenz Mar. 5, 1929 1,708,193 Sherwood Apr. 9, 1929 1,919,730 Koenig et al July 25, 1933 2,030,229 Schwarzkopf Feb. 11, 1936 2,146,823 Karrnazin Feb. 14, 1939 2,219,434 White Oct. 29, 1940 2,273,589 Olt Feb. 17, 1942 2,499,977 Scott Mar. 7, 1950 

1. THE PROCESS OF PROVIDING A SHAPED BODY COMPRISING METAL WIRE FILAMENTS EXTENDING THERETHROUGH WHICH COMPRISES THE STEPS OF PROVIDING A PLURALITY OF METAL WIRE FILAMENTS .001" TO .010" IN DIAMETER COATED WITH AT LEAST TWO LAYERS .00001" TO .001" THICK EACH OF SAID LAYERS BEING AN NON-POWDERED CONTINUOUS SUBSTANTIALLY HOMOGENEOUS SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF METALS AND OXIDES THEREOF OF DIFFERENT COMPOSITION THAN SAID FILAMENT, COMPACTING A GROUP OF SAID FILAMENTS UNDER PRESSURE SUFFICIENTLY LOW TO PREVENT ELONGATION AND CROSSSECTIONAL DEFORMATION OF SAIE FILAMENTS AND WHILE MAINTAINING SUCH PRESSURE THEREON, APPLYING HEAT TO SAID COMPACTED MASS AT A GRADUALLY INCREASING RATE TO ALLOY SAID LAYERS WITH EACH OTHER TO THEREBY JOIN SAID FILAMENTS TOGETHER, SAID HEAT BEING APPLIED AT A RATE WHICH PREVENTS THE TEMPERATURE OF SAID COMPACTED MASS FROM EXCEEDING THE MELTING POINT OF ANY COMPONENT THEREOF. 